Flockage apparatus for the decoration of diverse objects



Jan. 15, 1957 J. EVERARD FLOCKAGE APPARATUS FOR THE DECORATION OF DIVERSE OBJECTS 2 Sheets-Sheet 1 Filed Feb. 19, 1953 INVENTOR.

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FLOCKAGE APPARATUS FOR THE DECORATION OF DIVERSE OBJECTS Filed Feb. 19, 1953 2 Sheets-Sheet 2 O I 3 l I N I I I I I '1 I I r Q I T l' x x N u I I I M III III 'I l IIIIIIIIIIIIII IIII J.. I l J I 5 I Q% i o: I H

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|J0seph Everard United States Patent FLOCKAGE APPARATUS FOR THE DECORATION OF DIVERSE OBJETS Joseph Everard, Etterbeelr, Brussels, Belgium, assiguor to Otto Heimbach, Middletown, N. Y.

Application February 19, 1953, Serial No. 337,842

1 Claim. (Cl. 317-262) This invention relates to the coating of surfaces, and in particular to improved apparatus for electrically applying flock to diverse objects, including textiles, cardboard, or wall surfaces.

In the use of the described embodiment of the present invention the flock powder to be applied is placed upon an electrically conductive applicator plate, blade or scoop, and the applicator is charged to a relatively high voltage by means of a high voltage generator. The surface to be flocked is first coated with a suitable adhesive, and the applicator is then moved near the surface so that the flock, which becomes charged from the applicator, is attracted to the surface, which assumes an opposite charge by induction.

The apparatus prior to my invention were quite expensive and dangerous, requiring complete shielding and grounding. These prior apparatus weighed from 25 to 50 kilograms (55 to 110 pounds) and were satisfactory only for fixed installations such as those using a conveyor belt passing between electrodes.

It is an advantage of apparatus according to the present invention that they are relatively inexpensive and light in weight, being entirely encased in an oil bath so as to be safe, and yet being portable and even adapted to be strapped upon a users back for the purpose of applying flock to walls or to large areas of textiles such as on drapes or to other surfaces which cannot be reached by the fixed installation type of apparatus.

By the use of apparatus embodying the present invention one can obtain a flocked surface having the texture of velvet or of buck, or even a metallic-like surface, when powdered metal is used.

The various objects, aspects, and advantages of the present invention will be in part pointed out and in part apparent from the following description taken in conjunction with the accompanying drawings in which:

Figure 1 is a perspective view of the machine and a blade or scoop with its handle and attached cable;

Figure 2 is an enlarged view showing the way in which the flock is applied to a surface;

Figure 3 is a schematic electrical circuit diagram of the high voltage generating portion of the apparatus.

Referring to the drawings in greater detail, in Figure 1, generally indicated at 10, is the high voltage generating unit completely enclosed and mounted in a casing measuring 35 x 25 x 25 centimeters (approximately 14 x x 10 inches) and weighing approximately 17 /2 pounds. As explained more in detail hereinafter, this unit, which includes essentially a resonant circuit excited by impulses, furnishes the necessary 25,000 volts either to a plate located above the rectifier, or connected to a blade or scoop, forming a static current between plate or blade and a negative objective to be flocked. The plate is generally used for flocking in series, on paper, cartons, tissues, and objects of small dimensions. The blade or scoop is used for all vertical surfaces. This unit may be used also for the application of cork, leather, wool, Fibrane, abrasive, and metal powders.

The resonant circuit produces voltage peaks of about 8,500 volts which are applied to a voltage-tripling rectifying circuit giving about 25,000 volts at the output. Three diodes and their filtering capacities are mounted in a tight metal box 12 filled with oil. This box with two tubes also mounted inside forms a chassis requiring only a supply of 6.3 volts for the filaments and a high tension direct current of 350 volts. These voltages may be obtained by a separate supply. They may also be taken from the alternating supply of a radio receiving set. When the output current of the unit 10 exceeds 200 micro-amperes, the output voltage drops rapidly, which constitutes also a supplementary safety factor.

The power for the unit 10, which may be strapped on the users back or placed on the floor nearby, is obtained from the usual alternating current outlet of or 220 volts through supply wires 14, and the high voltage output is fed through an insulated, shielded high-voltage cable 16 to an applicator blade or scoop, generally indicated at 18 having a flock-supporting surface 19. The blade 18 has an insulated handle 20, and the high tension cable, which has a length of 2.5 meters or about 8 feet, is conveniently connected to the blade through this handle. Provision is made to adapt the unit 10 to various possible alternating current supply voltages, such as 110, 130, 220, 245 volts, by means of four sockets 21 and a button plug 22 which may be inserted in any one of the four sockets to provide the proper number of turns in the primary wind ing of the power supply transformer.

Figure 2 shows a portion of a hanging textile drapery 23 to which a flock is shown being applied from the scoop 18. In preparation for this flocking, the textile 23 is coated by a suitable adhesive 24. For example, one such suitable adhesive material is made from polyvinyl alcohol powder heated in water, which is stirred and brought to the boiling point and then allowed to cool. A layer will be noticed on the adhesive, which is removed, and it will be very limpid. This is acceptable for most uses, but in the flocking of textiles, to make the adhesive more pliable, a small quantity of glycerin, 14 or 15 grams for each liter of water, may be mixed in while the adhesive is warm.

After this adhesive 24 has been spread on the textile drape 23, for example, by brushing or by spray gun, the flock powder 26, which may be any of a wide variety of powders such as a textile powder or a metallic powder, for example, bronze, silver, aluminum, etc., is sprinkled upon the applicator blade 18. The unit 10 may be turned on by a switch 20, and when it is on, the red indicator light 30 is illuminated. The scoop 18, having a positive potential of 25,000 volts is moved to within approximately 10 cm. (4 inches) of the object to be flocked. The applicator scoop is lightly shaken in the hand of the operator and the flock 26 which is charged by the high positive voltage applied to the scoop, jumps toward the surface, which assumes a negative charge by induction, and sticks in the adhesive. Any flock which does not stick in the adhesive the first time returns to the scoop to be recharged and again flies against the adhesive.

In Figure 3 is shown a schematic diagram of the electrical circuits of the apparatus. in general, this includes a power supply, generally indicated at 32, an oscillator tube V1, an amplifier tube V2, and three voltage tripling diode rectifiers V3, V4, and V5 to provide an output voltage of 25,000 volts, and an output current in the range from zero to 200 micro-amperes. During normal op eration the output current may be approximately 40 micro-amperes.

One side of the wire 14 is connected to one terminal of the power transformer T3, and the other side is connected through the switch 28 to an adjustable primary as? tap arrangement, as mentioned above, with the plug 22 shown in the 110 volt socket.

The power transformer has a heater-current Winding P-F to supply the current for the heaters of tubes V1 and V2, and the light 30 is also connected across this winding. The plates of the power rectifier tube V6 are connected to a high voltage winding having its centertap connected to a common return circuit, and the heater of tube V is connected to a low voltage heater current winding. A filter choke L1 and filter condenser C11 connected between the line and the common return circuit are provided to smooth the 13+ plate supply voltage. A small condenser C2 is used to by-pass any higher frequency signals which might otherwise appear across the filter condenser C11.

The oscillator tube V1 a dual diode and triode in the same envelope, with its triode plate connected to the B+ plate supply voltage through the primary Winding of a blocking transformer T1. its grid is connected through a parasiticoscillation-suppressing resistor R1 and through the secondary of the blocking transformer T1 to the junction of a condenser C1 and a resistor R2 connected to the plate supply voltage 8+. This condenser C1, with its other terminal connected to the common return circuit, and the resistor R2, together with the secondary of the blocking transformer T1, are effective in forming a tuned-grid circuit and in determining the frequency of oscillation of the tube V1, which operates as a blocking oscillator and may have an audio frequency of oscillation.

The oscillation signal is coupled through a condenser C4 to the junction of two resistors R4 and R5. The resistor R4 is a parasitic-oscillation-suppressing resistor connected to the grid of the pentode amplifier V4, and the resistor R5 is a grid return resistor having its other end effectively connected to the common return circuit by a condenser C5. The voltage for the screen grid of the amplifier tube V2 is supplied from the B-] supply through a voltage dropping resistor R3 and is further filtered by the condenser C2 connected to the common return circuit. The cathode of the amplifier tube V2 is connected to the common return circuit through a cathode bias resistor R6 having a by-pass condenser C6.

The plate of the amplifier tube V2 is connected to a tap on the primary of a resonant autotransformer, having one end connected to the B+ supply and having the other end connected to a voltage-tripling rectifier circuit, generally indicated at 34.

In order to provide a grid-bias voltage for the ampli fier tube V2 and also to provide a control regulation for the amplification of the tube V2, the two diode plates of the tube V1 are connected to one end of an auxiliary winding on the transformer T2. This auxiliary winding has its other end connected through two series-connected resistors R2 and R7 to the common return circuit. The junction of these resistors Re and R7 is connected to the grid return resistor R5 to apply a negative bias to the grid, and the voltage across these resistors is filtered by the condenser C7. Thus, any tendency for the amplitude of the oscillations to increase tends to increase the voltage from the auxiliary winding, and the negative bias on the grid of the tube V 2 increases, which tends to compensate for the increased amplitude of oscillation, and vice versa.

The voltage-tripling rectifier circuit 34 is fed by a voltage of approximately 8,500 volts from the upper end of the primary of the transformer T2. This circuit includes three condensers Ca, C9, and C10 and three diodes V3, V 1, and V5 which have their heaters each connected to auxiliary secondary windings x-x, y-y, and zz 0n the resonant autotransformer T2 so that the heaters are energized by the oscillation frequency. It is an advantage of this arrangement that the diodes V2, V4, and V5 are completely isolated from the remainder of the circuit and together with the filter condensers Cs, C9,,

and C10 can be completely encased in oil.

The diode V3 has its cathode connected to the condenser C9, this tube and condenser are connected in series across the transformer T2 so that during alternate half-cycles the condenser C9 is charged to a peak voltage equal to the voltage from the transformer T2. In turn, the diode V4 has its cathode connected to the condenser C2, and this diode V4 and its condenser C2 are connected in series across the first diode V3, so that during the other half-cycles the condenser Cs is charged to a still higher peak voltage. in turn, the diode V5 is connected in series with the condenser C10 across the diode V4. The high-voltage output terminal is connected to the last condenser C10 so that a direct current output voltage of approximately 25,000 volts is obtained.

Among the advantages of the voltage-increasing-rectifying circuit 34 is its safety factor due to its poor regulation, whereby any increase in the output current above about 200 micro-amperes causes a great reduction in the output voltage. This elicct is increased by the fact that any increase in the output current decreases the voltage available from the filament windings x-x, v-y, and hence reduces the temperature of the diode cathodes, thus further dropping the output voltage.

The values of the elements in the circuit may be as follows: the diode tubes V3, V4, Vs8,500 volts on the plate.

Resistances: R140 ohms, 0.25 watt; R260,000 ohms, 0.5 Watt; R34,O00 ohms, 1 watt; Ila-40 ohms, 0.25 watt; R5-l50,000, 0.25 watt; Rsl20 ohms, 1 Watt; liq-550,000 ohms, 0.25 Watt; Rsl,500,000 ohms, 0.25 watt.

Capacities: C1rnica condenser, 4,000 micromicrofarads, 5 C2paper condenser, 0.1 microfarads, 10%, 600 volts; C3electrolytic condenser, 25 microfarads, 500 volts; C4-paper condenser, 12,000 micromicrofarads, 10%, 4-00 volts; Cspaper condenser, 15,000 micromicro-farads, 10%, volts; Ceelectrolytie condenser, 25 microfarads, 25 volts; C3, C9, C1uelectrolytic condensers, 40 micromicrotarads, 10,000 volts; C11electrolytic condenser, 12 microfarads, 500 volts.

Transformer T1 is a blocking transformer with a ratio of 1:3. Transformer T2 is a resonant autotransformer with a low loss core. Transformer T3 is a supply transformer with input taps of 110, 130, 220, and 245 volts and having a high voltage secondary 2 375 volts, a 6.3 volt winding F-F for the heaters, and 5 to 6 volts for the power rectifier heater. A full wave rectifier is used, and the filter condenser may be from 8 to 25 microfarads and the choke L1 from 10 to 50 henries.

A series resistance of 1,000,000 ohms is included in the 25,000 volt output cable 16, which with the capacity of the exterior shielding serves as a safety arrangement in case of short circuit in the output circuit.

The strength of the power supply current is 47 milliamperes for 200 micro-amperes output; and 26 milliamperes for zero output current.

I claim:

Portable apparatus for applying flock to an object comprising a conductive applicator having a surface on which the flock may be placed, a high-voltage conductor connected to said applicator, and a high-voltage generator connected to said conductor for electrostatically charging said applicator whereby any flock thereon will become charged, said generator including an oscillator circuit, a voltage-increasing circuit coupled to said oscillator circuit, and a rectifying circuit coupled to said voltage-increasing circuit, the output terminal of said rectifying circuit being connected to said conductor, said generator being completely encased in an insulating medium.

References Cited in the file of this patent UNITED STATES PATENTS 1,854,071 Schacht Apr. 12, 1932 2,509,277 Ransburg et al. May 30, 1 950 2,647,228 Just July 28, 1953 

